Airplane construction



June 5, 1934. 9 s. 1'. WILLIAMS 1,961,996

' AIRPLANE CONSTRUCTION Filed March 2, 1932 5 Sheets-Sheet 1 INVENTOR,seldenfm'lliamfi BY I (W W ATTORN EY;

u 5, 1934- s. T. WILLIAMS 1,961,996

AIRPLANE CONSTRUCTION Filed March 2, 1932 5 Sheets-Shet 2 INVENTOR SldenZ'M'llz'ams BY M M 7 K44 ATTORN EYS June 5, 1934. s. 'r. WILLIAMSAIRPLANE CONSTRUCTION 5 Sheets-Sheet 3 Filed llarch 2. 1932 INVENTOR S aI w 0 A M a uY B June 1934- s. T. WILLIAMS 6 ,996

AIRPLANE CONSTRUCTION Filed larch 2,1932

5- Sheets-$heet 4 INVENTOR Seldm Z'mm'm;

ATTORNEY! 7 June 5, 1934. s. T. WILLIAMS 1,961,996

AIRPLANE CONSTRUCTION Filed March 2. 1932* 5 SheetswSheet 5 \INVENTOR58mm 11mm BY r ATTORNEYS Patented June 5, 1934 orries CONSTRUCTIONSeldcn '1. Williams, Bellerose, Y. Application March 2, 1932, Serial No.596,211

11 Claims. (Cl. 244-19) This invention relates to airplane and airfoilconstructions, particularly of the class having wing structures designedfor auto-rotation.

The objects of this invention include the pro- 6 vision of wingstructures and arrangements thereof of the above indicated classadaptable for use in aircraft to provide improved efllciency,flexibility of control and lifting power with a high degree of safetyand stability without sacriiice of speed.

Various further and more specific objects, features and advantages willclearly appear fromthe detailed description given below, taken inconnectlon with the accompanying drawings'which form a part of thisspecification and illustrate, merely by way of example, certainembodiments of the invention.

The invention consists in such novel features, arrangements andcombinations of parts as may be shown and described in connection withthe structures herein disclosed, by way of example only, and asillustrative of preferred embodiments. v

- In the 'drawings' Figs. 1, 2 and 3 are plan, front and side viewsrespectively of an airplane constructed according to my invention in oneof its embodiments;

Fig. 4 is a plan view partly in section and partly broken away, showingone of the rotating wing structures of such an airplane;

Fig. 5 is a side view partly in section of the wing structure, showingFig. 4; Fig. 6 is an enlarged sectional view taken substantially alongthe line ,6-6 of Fig. 4, and showing in further detail, features of thewing structure of Figs. 4 and 5;

Fig. 7 is a vertical sectional view taken substantially along the line7-.-7 of Fig. 6, showing further details;

Figs. 8 and 9 are views similar to Figs. 4 and 5 respectively, butshowing an alternative embodiment of my invention; Fig. 10 is a planview partly broken away of still another wing structure embodying myinventicn;

Figs. 11 and'12 are sectional views taken substantially along the line11-11 of Fig. 10, showing the movable parts in two different operativepositions; a

Figs. 13 and 14 are sectional views respectively illustrating in furtherdetail various parts of a structure such as of Fig. 10; and

Figs. 15, 16 and 17 are plan, front and side views respectively of anairplane including an alternative embodiment of my invention as\appliedto a- "pusher type airplane with a sweep back wing structure.

The airplane shown in Figs. 1, 2 and 3 may be provided with a fuselage20, propeller 21, horizontal stabilizers as at 22, elevators as at 23, a

rudder 24, a vertical mi 25 and landing gear 26, all of these partsbeing of conventional or well-known forms. The particular constructionshown in these figures may also be provided with a pair of.comparatively small'lower wing panels as at 27 and 28 provided withailerons of conventional type as indicated at 29. These lower wingpanels'not only serve as auxiliary wings in horizontal flight but alsoprovide a convenient means for carrying the ailerons for lateral controlof the plane and to provide a structural support for the rotating wings,hereinafter described.

As is indicated at 30 and 31, I have provided a pair of upper wingstructures in the form of circular auto-rotatable disc-like airfoils,each of which has hinged at spaced points to the periphery thereof aplurality of supplemental wind driven airfoils as at 32 extending in agenerally radial direction in respect to the disc-like members. Asindicated in Figs. 2 and 3, these rotats0 able airfoils may for examplebe supported upon the lower wing structure as by a suitable tripodstructure which may comprise a vertically extending pylon 33,cooperating with forwardly and rearwardly extending bracing struts as at34 and s1, 35. However, it will be understood that other forms ofsupporting means might be provided for the rotating wing elements andattached for example directly to the fuselage. If desired, the tripodstructure may be strengthened as by the use of lift wires indicated at36 and 37. The lower wing panels may be braced and retained as by theuse of struts 38 and landing wires 39.

As indicated in Fig. 2, the wing structures 30 and 31 arepreferablyarranged at a slight dihedralangle in respect to each other toassure automatic banking upon turning the airplane and to improve itsstability in flight. That is, the spindles as at 40 (see Fig. 9) uponwhich these elements rotate, are preferably tilted upwardly and inwardlytoward the fuselage. Also, as is indicated in further detail in Fig. 9,the rotatable elements are. preferably mounted on call or conventionalroller bearings to readily permit the desired auto-rotation of theseelements during flight. As is indicated by the arrows in Fig. 1, therotatable wing structures 30 and 31 are intended to rotate inopposite'directions, the wing 30 for example rotating counterclockwiseand the wing 31 clockwise, as viewed in Fig. 1. By

hicle wheels 2 reason of this counter rotation the gyroscopic effectsare counterbalanced or compensated, thus rendering the airplane inflight more fully susceptible to control by the pilot.

The rotatable wing structures may take'various forms, which will now bedescribed in further detail. Referring to Fig. 4, a hub member 41 isprovided at the center of a wheel-like structure having spokes 42 formedof wire for example, and attached at their outer ends to a rigidrim-member 43. As is indicated in Fig. 5, some of the spokes may beconnected to the upper end of the hub and others to the lower end,whereby a series of concentric annular members as at 44 may be mountedthereon to provide over the top and bottom surfaces of the wheel-likestructure a support for the covering material 45 following the contoursof the desired airfoil shape. The members 44 may be secured to the wirespokes 42 as by welding or by binding with wire, as indicated at 46 inFig. 9. The covering material 45 may comprise airplane cloth suitablydoped in any well-known manner. The spokes 42 at the points where thesame are joined to the rim 43 may be threaded or otherwise provided withmeans permitting tightening of the spokes in a manner similar to theconstruction of vehaving wire spokes.

The surface contours of the circular airfoil are preferably soconstructed as to provide a relatively stable center of pressure forthese members, regardless of the angle of incidence that the'same mayassume during flight. For this purpose, these elements may beconstructed so that the forward half of any vertical section extendingparallel to the line of flight, will have contours approximating forexample that of the well-known Gtittingen section #429. However, anyvariation of the center of pressure on these elements may be compensatedfor by adjustments of the horizontal stabilizer 22 and the elevators 23.

In horizontal flight these circular airfoils will act as standardairfoils and add to the lift of the rotating-wing surfaces. Furthermore,I have found that such revolving airfoils possess lifting advantages inthat the low pressure area above the wing and the high pressure areabelow such wing is substantially increased on advancing through the airat a positive angle of incidence. The-low pressure area above and thehigh pressure below the wing structure is also augmented during descent.In addition, these circular airfoils cooperate with the wing elements 32hereinafter described to increase the lifting power thereof under allconditions of flight. That is, the circular airfoils tend to increasethe amount of air passing the wing elements 32, thereby increasing theirdynamic action.

For purposes of illustration 1 have shown each of the circular airfoilsas provided with four autorotating airfoil elements 32, although undersome circumstances a greater or lesser number may be found to bedesirable. As indicated in Fig. 4 each of these members may be fastenedas by a hinge 47 to the rim 43. These airfoils are shown as being of agenerally rectangular outline and the section or form thereof may besimilar to that of a conventional airplane wing. In fact, each is anindividual airplane wing constrained to glide on a circular flight pathunder the action of the air due to the motion of the airplane throughthe air. Each of these rectangular wings is attached to the circularwing at such an initial angle of incidence as to maintain auto-rotationwith the desired rate of rotation, lift and wing position. The hinges at4'7 permit these airfoils to hinge upwardly or downwardly and ifdesired, a universal joint type of hinge may also be employed tov permitfore and aft movement. Constructions of such type will be describedhereinafter. Rotation of these rectangular airfoils on their own axesis, however, not permitted or else is restricted within predeterminedlimits, as will be hereinafter explained. With the horizontal hingestructure as shownin Figs. 4 to '7, however, only the flapping motion ispermitted.

Referring to Figs. 6 and '7, the hinge structure 4'7 and connected partswill now be described in further detail. In the particular example hereshown, the rim 43 is partially embraced by a hinge'pintle carryingmember 48 secured as by a dowel 49 and radial spokes 42 to the rim 43.The hinge pintle 50 is embraced by a cylindrical member 51 which haswelded or otherwise secured thereto a U-shaped member 52, the arms ofwhich may be riveted or otherwise secured to a pair of channel members53 and 54 which comprise a rigid central support for the wind drivenairfoil or wing .elements 32. As shown in Fig. 4, wing ribs as at 55 maybe mounted on the members 53 and 54 for carrying the wing coveringmaterial. The inner edges of the wing element may be strengthened andstreamlined by a rigid member 56 secured to the hinge member 52. Themember 56 may be formed with edges cut at an angle as shown at 5'7 and58 at points below and above the hinge member 48. These angles are suchas to limit respectively the extent of the downward and upward movementof thawing element. When the airplane is at rest, for example on theground, the wing elements 32 will be supported against dropping to avertical position by reason of the engagement of the angular surface 57with the hinge member 48. The wing elements will therefore be heldagainst dropping to a position where it might be dimcult for the planeto properly start in flight. Also, if the plane in flight shouldencounter some extremely abnormal condition, the wing elements 32 willbe held against flapping to a vertical position by reason of theengagement of the angular surface 58 with the hinge element 48.

A semi-articulated means for attaching the wing elements 32 to thecircular airfoils will now be described in connection with Figs. 8and'9. In this construction a hinge member may be provided at 60 similarto the hinge above described, with the exception that instead ofproviding a rigid attachment to the circular rim, the hinge 60 ismounted upon a ing internally of the circular airfoil and pivotedvertically at 62 adjacent the center of the circular airfoil. With thistype of structure the circular airfoil becomes of secondary importancein the support of the rectangular airfoils. The hinge at 60 ofcoursepermits the up and down "flapping motion of the rectangularairfoil and while fabricated arm 61 extend rotation of the circularairfoil about its own axis Also, in the particular construction shown inthese figures, a comparatively small number of rigid spokes as at 65 areprovided in lieu of the smaller or wire spokes for the circular airfoilas above described. In order to limit to some degree the forward andrearward turning movement of the wing elements 32 about the verticalpivots as at 62, and to yieldingly retain these wing ele ments in anormal position, flexible connections as at 66 may be provided to extendbetween the hinge members of the adjacent wing elements 32;

As indicated in Figs. 8 and 9, these flexible connections may comprisein part wires or cords with springs interposed, the ends of the wiresbeing attached in suitable eyelets 6'7 formed on the sides of the hingemembers. 2

Another arrangement for attaching the rectangular airfoils to thecircular airfoil is illustrated in Figs. 10 to 14 inclusive. With thisarrangement, a universal joint member is secured in a mounting in thecircular wing structure at the root of each rectangular airfoil adjacentto the periphery of ihe circular airfoil. This universal joint permitsan up and down or flapping inotion by reason of the rotation of a smallshaft or pintle member 68, to which the rectangular wing element isfixed as by arms 69. The central portion of themember 68 is providedwith a spherical enlargement 70 and the end portions of the member 68may be provided with enlarged cylindrical bearing surfaces 71 and 72,which slide respectively in arcuate grooves 73 and 74, these groovesbeing formed in rigid members as at 75 attached to the peripheral rim ofthe circular airfoil. The spherical portion '70 is embraced by a member76 having upper and lower arms as at '77 and '78 respectively, thesearms being attached to wires or rods'79 and 80 respectively, in each ofwhich may be interposed a spring as at 81, the rods or wires thenextending to points near the center of the circular airfoil where theymay be suitably fixed. This mechanism may all be enclosed withinsuitable housing means as at 82 wihin the circular air foil structure.It may be found desirable to increase somewhat the thickness of thecircular airfoil at its. periphery at the areas 83 adjacent therectangular wing elements in order to accommodate this mechanism anditshousing and to provide a flexible shroud over the junction to fair thewing structures.

With the abovedescribed mechanism it will be apparent that when theforces on the wing elements 32 are such as to tend to cause theseelements to either lag back of or proceed in ad vance of the rotationof. the circular airfoil, then if such lag or advance becomes effective,the

ange of incidence of the wing element will also be varied. That is, thewing element will be forced to rotate on its own axis because of'themovement of the bearing members 71 and 72 in the slots 73' and 74; theseslots being at the same angles to the horizontal, as is indicated inFigs. 11, 12 and 14. In Fig. 11 the parts are shown in normal positionwhereinthe wing elements 32 extend directly outward radially. In Fig. 12the parts are shown in the positions assumed when the wing element 32 ismoved to a position in advance of the rotation of the circular airfoil,

viewing the parts as indicated in Fig. 10, at 11-11. It will beunderstood that the rods or wires 79 and 80 W1 h their interposed springelements cause the member 76 to somewhat yieldingly engage the sphericalmember'IO while permitting the wing element 32 and its supporting hingestructure to assume its natural position, dependtion of the wing elementon its'own a'xis however being restricted to adegree depending upon theangular positions of the slots 73 and 74. When the rotating wing comesto a position of rest, the wing elements 32 will droop down eventuallyto a position where the arms 69 will contact with and be supported bythe lower outer edge of the housing 82 at a point indicated in Fig. 14,at 84. Of course other means such as guy wires may be used to restrictthe downward movement of these wing elements but it will be appreciatedthat such checking or restricting is not an essential funciioning partof the rotating wing mechanism during its operation.

The operation of these rotating wing structures in supporting theairplane in flight will now be described.

Prior to flight, the rotating wing structures must be placed inrotation, but once in rotation the motion of the airplane through theair will auto-rotation. This initial rotation may' be secured from theairplane engine through the use of suitable shaft and clutch mechanisms,such for example as have heretofore been used in connection with theautogyro. Such mechanism is disconnecied after the required speed ofrotation is secured and before the airplane starts its flight. Initialrotation may also be imported manually if desired or merely bydeflecting a current of air from the airplane propeller on to therotating elemen's. When the rotator wing elements are placed in rotationas above described, centrifugal force tends to throw the wing elements32 upwardly into horizontal positions. As the airplane starts its flightby taxiingover the ground at increasing speed, the air flow through therotating wing structures increases. This causes the lift of the circularairfoil, as well as that of the wing elemen s 32, to build up until theairplane is carried up into theair in flight.

As previously stated, each rectangular wing functions similarly to anairplane wing when gliding and auto-rotation is the result of theconstraint of the glide to a circular flight path. The lift on therectangular airfoils tends to swing (or cone) them upward and this iscounter: acted by the centrifugal force of the rectangular airfoils dueto the rotation. The resultant of the centrifugal and lift forces of therectangular airfoils essentially cancel in the plane of rotation, andare additive in the vertical, applying lift to the structure.

In horizontal flight, it will be readily understood that the rate anddirection ,of the airflow over the rectangular airfoils varies as thewing structure rotates. 0n the advancing side, the relative velocitybetween air and airfoil increases until the rectangular airfoil underconsiderationis at right angles to the path of flight. It then decreasesuntil the individual airfoil is again at right angles to the path offlight on the retreating side of rotation.

As the lift of an airfoil is a function of air lution. Various otherforms only travel at a fore obvious rectangular ing rotation, positions.The arrangement shown in Figs. 10 to 14 inclusive is adapted toaccomplish this purpose. The form of the guides or slots 73 and 74 is sochosen as to vary the angle of incidence of the wing elements 32with theadvance or retreat of the airfoil, as above described, in such a manneras to equalize the lift throughout revoof mechanism might also beprovided for accomplishing the result as regards varying the angle-ofincidence in such manner that the wing is free to flap and to pivot andwhereby such pivoting brings into action a turning mechanism that variesthe angle of incidence. I

With the above described constructions the use thatif the angle ofincidence of the airfoils may be properly varied durof relatively longand heavy auto-rotating rectangular airfoils is avoided. With such longairfoils as heretofore used, although the outer ends thereof travel at arelatively high speed and with high efficiencies, theinner portionswhich can low rate of speed, are much less effective, especially whereno central circular airfoil is provided. The speed of rotation of'suchbeen relatively low-at about 125 R. P. M. However, with theconstructions embodying my inmay be much greater-for example 300 R. P.M. or more-and comparable lifts secured from smaller rotating wingstructures. In addition, the greatest horizontal speed of the airplanemay be small in relation to the rotational velocities of theauto-rotatableairfoils. If the velocity due to rotation is great, andthat due to forward advance in flight is small, the variation in lift onany individual rotating airfoil will be small during its revolution,thereby making possible smooth stable flight with a high degree ofefliciency for the rotating wing elements. The support given by thecircular rotating airfoils at the center of the rotating structuresserves to substantially increase the support afforded by theauto-rotatable elements. The above described arrangement, having aminimum of two rotor wings, permits ready access and egress from thecockpit or cabin of the plane either in flight oron the ground, evenwhile the wings are rotating. This arrangement also provides a compactsymmetrical structure in which the parts may be easily replaced,serviced or inspected. The relatively small diameter of the circularairfoil permits retaming the variations of the center of pressure withincontrollable limits while still permitting elements also makes itconvenient to use the dihedral mounting, assuring proper banking. onthe-turns.

However, my invention in various ofits phases is adaptable to machineshaving more than two of the auto-rotatable structures. .FQL example,inFlgs- 15 to 1'7 inclusive, 1 have shown a machine of the pusher typehaving sweep-back'lower wing panels, the conventional upper wing panelsbeing replaced by auto-rotatable structures as at 90 and 91 constructedsimilar .to the rotatable structures above described and also designedto rotate in opposite directions as arrows. .[nv addition, I haveprovided at 92 a third and preferably somewhat smaller auto-rotatableelement also of similar construction and mounted in advance of theforward end of the cabin in a constant lift may be secured at all longauto-rotatable airfoils heretofore used has.

vention as above described, the speed of rotation the use of relativelyhigh and efficient rotor. speeds. The use of a pair of theauto-rotatable indicated by the a position somewhat lower than, thestructures 90 and 91. As is indicated in Fig. 17, the shaft upon whichthe structure 92 rotates may be mounted so as to be tiltable forwardlyor rearwardly' by suitable means'such as indicated at 93, manuallyoperable from the control stick in the same manner that conventionalelevator surfaces are operated.

While the invention has been described in detail with respect toparticular preferred examples, it will be understood by those skilled inthe art after understanding the invention that various changes andfurther modifications may be made without departing from the spirit andscope of the invention, and it is intended therefore in the appendedclaims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A rotating wing structure comprising a disclike freely rotatableairfoil and a plurality of auto-rotatable wing elements hinged theretoalong lines substantially tangent to the periphery there- 0 2. Arotating wing structure comprising a disclike centerportion, a pluralityof substantially radially extending wing elements at the peripherythereof, and means for mounting said wing elements for pivotal movementabout vertical axes at the mid portion of the structure, and alsopivotal movement about horizontal axes extending transversely of thewing elements.

3. A rotating wing structure/comprising a disclike center portion, aplurality of substantially radially extending wing ery thereof, meansfor mounting said wing elements for pivotal movement about vertical axesat the mid portion of the structure, and also-pivotal movement abouthorizontal axes extending transversely of the wing elements, and meanscontrolled by said last described pivotal movement for tilting said wingelements about axes extending in a generally radial direction.

4. A rotating wing structure comprising a disclike center portion havinga plurality of autorotatable wing elements extending from the peripherythereof, and means for mounting said wing elements in respect to saidcentral portion,

"permitting pivotal movement of said wing elements about substantiallyhorizontal axes extending transversely of said wing elements, and meansunder the control of such pivotal movement for varying the angle ofincidence of said wing elements by and in accordance with such pivotalmovements;

5. An airplane comprising a fuselage, propeller means mounted thereon,wings of the sweepback type extending therefrom, auto-rotatable airfoilstructures mounted at each side of said fuselage in spaced relation tosaid wings, and another auto-rotatable airfoil structure mountedsubstantially on the longitudinal axis of the fuselage. 6. A rotatinswing structure comprising a rotatable disc-like element having aplurality of wind driven airfoils located at spaced points around itsperiphery, the direction in which said airfoils extend in respect tosaid periphery-being variable with variations in the air forces thereon,and means housed within the'disc-like element for interconnectingadjacent airfoils whereby variations in the position of one of themcauses a force to be applied to the adjacent airfoils tending to varythe positions of the latter. 1

7. A rotating wing structure'comprising a free- Iy rotatable disc-likeelement having a plurality of wind driven airfoils located at spacedpoints around its periphery, said element having the form in crosssection of a symmetrically uniformly cambered lifting surface, each ofsaid airfoils being mounted pivotally about an axis extending in agenerally perpendicular direction in respect to said element whereby thedirection in which each airfoil extends in respect to said periphery isvariable with variations in the air forces thereon.

8. A rotating wing structure comprising a disclike freely rotatableairfoil and a plurality of auto-rotatable wing elements protruding fromits periphery and hinged to the disc-like airfoil along lines extendingtransversely of said wing elements.

9. A rotating wing structure comprising a disclike freely rotatableairfoil and a plurality of auto-rotatable wirig elements protruding fromits periphery and hinged to the disc-like airfoil along lines extendingtransversely of said wing elements, said lines extending substantiallyparallel to the general plane of the disc-like airfoil.

10. A rotating wing structure comprising a freely rotatable surface,substantially a surface of revolution, shaped like a discus, saidrotatable surface having the form in cross section of a symmetricallyuniformly cambered lifting surface such that when in flight at variousangles of incidence in the neighborhood of the horizontal, the center ofpressure against the struc- -ture remains substantially constant, and aplurality of wind driven airfoils located at spaced points around theperiphery of said rotatable surface.

11. A rotating wing structure comprising a freely rotatable surface,substantially a surface of revolution, shaped like a discus withsymmetrical uniform cambered upper and lower surfaces whose maximumcamber is at theaxis and having a plurality of wind driven airfoilssecured thereto adjacent its periphery, said airfolls being attachedpivotally and being free to assume various positions depending uponcentrifugal force and the force of air-currents thereon.

SELDEN T. WILLIAMS.

